Olhaye graduated from the Commercial School of Addis Ababa, Ehtiopia, in 1964 with an Intermediate Diploma in Commerce. He qualified as a professional accountant in England in 1972. Olhaye began his career in 1964, holding positions in auditing, accountancy and taxation in Ethiopia. He stayed in that field until 1973, when he was appointed Regional Chief Accountant for TAW International Leasing Corporation in Nairobi. He became Financial Director, Africa, for that firm in 1975. In 1982, he founded the Banque de Djibouti et du Moyen Orient, S.A., as a joint venture with another bank in the Middle East. Earlier, he had served as an independent consultant concentrating on financial issues.
Olhaye’s public service career began in the early 1980s. From 1980 to 1985 he was Honorary Consul of Djibouti to Kenya, during which time the two countries established diplomatic relations. From 1986 to 1988, Olhaye served as Djibouti’s Permanent Representative to the United Nations Environment Programme (UNEP) and United Nations Centre for Human Settlements (Habitat) in, Nairobi. In 1988, he was appointed ambassador to the U.N. and to the U.S., posts he has held ever since. During his term in office, Mr. Olhaye has represented his country in the Security Council, served as President of the Council (February 1994) and Chairman of the Sanctions Committee established by Security Council resolution 841 on Haiti. In August 1994, as a member of the Security Council Mission to Mozambique, he assisted in the process towards democratic elections. He has also participated in numerous international conferences and meetings As the longest-serving ambassador to the Unites States, Olhaye holds the post of Dean of the Diplomatic Corps in Washington D.C.